It is well-known that it is often necessary to reproduce flat keys for numerous applications such as door keys, ignition keys for cars, keys for door locks, suitcases or various items of furniture, and there are at present automatic machines which make it possible very rapidly to reproduce profiles of specimen keys from blanks of suitable form. Indeed, the various flat keys are distinguished from one another not only by their profile but also by their length, their width and mainly by their cross-sectional form: the result is that the locksmith must have available a very large number of blanks of different types, from which he must find out the blank which is likely to be suitable for reproducing a specific specimen key. In order to facilitate the search, it has already been proposed to provide dispensers comprising magazine containers each containing blanks of a type which corresponds to a model of key of one maker (indeed, keys generally bear the name of either the car manufactures, or lock manufactures, and also a reference number or code), such magazines being provided with means of extracting or ejecting a blank, operated by a selector mechanism triggered by insertion of the specimen key into a template comprising slots, the cross-sectional form of which is identical to that of the specimen key. In principle, therefore, it is sufficient to designate the slots of the template by the trade mark (name of manufacturer and number) of the corresponding specimen key in order to obtain immediately the desired key or indeed, if the specimen does not bear the necessary information, to try to insert it successively into different slots in the template which at first sight are of similar form. However, the known dispensers of this type, whether they comprise magazines in the form of flat juxtaposed boxes each of which has an ejector device, or a rotatable structure having radial cells in which the blanks are stacked and which are, by rotation of the drum around its axis, automatically positioned opposite an extractor or ejector, are extremely cumbersome and mechanically complicated, which makes it impossible to provide therein a number of cells adequate to hold the majority of the types of blanks corresponding to the various existing model of keys, even those used most commonly in various applications.